WPF: Editable ComboBox; how to make the search / autocomplete function case sensitive?

Let's say I have ComboBox

, for example:

<ComboBox IsEditable="True" Height="30">
    <ComboBoxItem>robot</ComboBoxItem>
    <ComboBoxItem>Robot</ComboBoxItem>
</ComboBox>

      

        
        
        
      

    

If the user comes in and starts by typing a lower case r into this ComboBox

one when it is empty, it is ComboBox

predictably auto-filled with the word by the robot . Excellent.

Now the same user comes in and starts typing an uppercase R into this ComboBox

one when it is empty again. Unpredictable, ComboBox

auto-filled with robot lowercase word . Not good. I desperately want it to auto-fill itself with Robot , but WPF doesn't seem to want to smile at me.

Whatever you do (CAPS lock, shift + key) ComboBox

will always be auto-filled with a line robot, provided that the lowercase Robot precedes the uppercase Robot in the item collection ComboBox's

.

Is there a way to prevent this? This behavior is insane and makes the user experience absolutely terrible.